Sore Points on Treating Sore Throats

Abstract & Commentary

By Eileen C. West, MD, Director of Primary Care Women's Health, Clinical Assistant Professor of Internal Medicine, University of Oklahoma School of Medicine, Oklahoma City, Oklahoma. Dr. West reports no financial relationship to this field of study.

Synopsis: Clinicians seem not to follow any of several recommended guidelines when evaluating and treating pharyngitis and, as a result, there is widespread over-treatment with antibiotics.

Source: Linder JA, et al. Evaluation and treatment of pharyngitis in primary care practice: the difference between guidelines is largely academic. Arch Intern Med. 2006;166:1374-1379.

When was the last time you caved in and gave antibiotics, even though you weren't convinced the patient had strep throat? Apparently, you are not alone.

Every year, patients in the United States make about 11 million visits to a health care provider that result in a diagnosis of pharyngitis. Approximately 10% of adults with pharyngitis will have group A beta-hemolytic streptococci, the only common cause of sore throat for which antibiotics are indicated. However, 70% of American adults with pharyngitis are treated with antibiotics. Everyone seems to agree that the antibiotic prescribing rate is too high, but there is disagreement about the best way to evaluate and treat adults with pharyngitis.

The American College of Physicians (ACP), the American Academy of Family Practice and the Centers for Disease Control and Prevention together recommend the use of the 4-point Centor criteria in evaluating adults with pharyngitis. These criteria are: 1) subjective or objective fever > 100.4°F, 2) absence of cough, 3) tender anterior cervical lymphadenopathy, and 4) tonsillar exudate.1

The ACP guideline then recommends two possible strategies.2 The ACP EMPIRICAL STRATEGY suggests empirical treatment of patients who meet 3 or 4 Centor criteria. The ACP TEST STRATEGY suggests: 0 or 1 criteria met—no test or treat, 2 or 3 criteria—test using a rapid antigen detection test and prescribe antibiotics to patients with a positive test, 4 criteria-treat. The Infectious Diseases Society of America (IDSA) agrees with no testing or treating patients with 0 or 1 criteria, but recommends microbiologic confirmation for all adults with pharyngitis prior to antibiotic prescribing.3 The authors of the IDSA guideline have openly disagreed with the ACP guidelines stating that use of clinical criteria alone results in overprescribing antibiotics to patients unlikely to have streptococcal pharyngitis.

In their retrospective analysis of over 2000 visits to Boston area primary care sites for pharyngitis, Linder et al study adherence to established guidelines to evaluate patients for strep pharyngitis. The results show that not only is there disagreement about which guideline to follow, but in 66% of visits, no guidelines are followed at all. Most of the nonadherence (78%) is related to testing and treating patients with few clinical criteria for pharyngitis.

In these academic-affiliated practices, 80% of visits included a streptococcal test (rapid antigen detection [RADT] in 25%, throat culture in 39%, both in 16%). 33% of tests in the RADT only group were positive, 15% of the culture only group were positive, and in the group where both tests were performed, 12% RADT and 15% of cultures were positive.

In this study, clinicians prescribed antibiotics in 47% of visits overall. While lower than national rates, it still far exceeds the expected prevalence of strep throat. Those given antibiotics were younger, had symptoms for a shorter time, and had a higher mean temperature. Prescribing was more common for patients with Centor criteria. The lowest prescribing rate (24%) was found in the clinic with a 100% testing rate and the highest (77%) was found at the clinic with the lowest testing rate. Among patients who had a positive streptococcal test, 98% received antibiotics. Among those with a negative test, 30% received antibiotics. Of all antibiotics given, 35% went to those with a positive test, 40% went to those with a negative test, and 24% went to those with no testing. Antibiotics were overprescribed in general, but in particular nonrecommended antibiotics were used 40% of the time. Penicillin remains the antibiotic treatment of choice.

Commentary

There has been extensive debate about the best way to approach ambulatory patients with pharyngitis. Most of the debate focuses on how to test and manage patients with more severe pharyngitis who meet several well-defined clinical criteria.

As Centor himself points out in an editorial in the same issue,4 the management of adult pharyngitis rarely receives attention in residencies or CME programs. Yet is it one of the most common reasons for office visits. As the study shows, clinicians may be ordering tests but are not using the results to determine treatment. Adhering to any of the guidelines discussed above showed only modest differences in the antibiotic prescribing rate overall. By far the biggest issue was excessive testing and treating of patients with few or none of the established clinical criteria. It seems that in order to prevent unnecessary antibiotic use, which guideline to use is not as important as adhering consistently to one of the guidelines.

The bottom line is regardless of which guideline you choose, avoid testing and treating patients at low risk for streptococcal pharyngitis, particularly those with viral symptoms, such as cough, nasal congestion, or pharyngeal vesicles. Second, penicillin remains the antibiotic of choice because it is effective, well tolerated, and inexpensive and group A (beta)-hemolytic streptococci are universally susceptible.

References

1. Centor RM, et al. The diagnosis of strep throat in adults in the emergency room. Med Decis Making. 1981;1:239-246.

2. Snow V, et al. Principles of appropriate antibiotic use for acute pharyngitis in adults. Ann Intern Med. 2001;134:506-508.

3. Bisno AL, et al. Practice guideline for the diagnosis and management of group A streptococcal pharyngitis. Clin Infect Dis. 2002;35:113-125.

4. Centor RM, Cohen, SJ. Pharyngitis management: focusing on where we agree. Arch Intern Med. 2006;166:1345-1346.